Sea Shepherd's $12m new custom-built vessel arrives in Australia

The captain wryly says the ship is built for speed, not comfort, but Sea Shepherd hopes its new rugged fast-boat will be a "game changer" in its battle to stop Japanese whalers.

The $12 million custom-built vessel, christened Ocean Warrior, made its first port of call in Australia on Tuesday, tying up for a customs inspection at Melbourne's Williamstown dock and preparing for a protest campaign against Japan's whaling fleet in the Southern Ocean.

"Going down there, it's been really difficult going head-to-head with the harpoon ships because they could always run away," said the ship's captain, Adam Meyerson.

But he said the Ocean Warrior - with its four engines and specially-installed long range fuel tanks at the expense of extra accommodation berths or storage - was capable of speeds to outrun any ship in Japan's whaling fleet.

About the size of an Olympic swimming pool, the ship is also equipped with a helicopter landing pad and a water cannon that Sea Shepherd said can spray about 20,000 litres each minute.

The new ship - and the likelihood of high-seas protest clashes over the summer - looks set to raise the tension around Japan's decision to resume killing whales after the hunt being ruled illegal by the International Court of Justice.

Chinese television was among the media at Williamstown, with Beijing and Tokyo in regular dispute over questions of international law.

Australia last month successfully lobbied for greater international scrutiny of Japan's claim its whale slaughter is for "scientific" purposes, with Environment Minister Josh Frydenberg hailing the decision as a "big win" at the summit of the International Whaling Commission.

Sea Shepherd's captain Adam Meyerson, pictured in the Ocean Warrior, is about the embark on his fourth protest campaign in the Southern Ocean.Credit:Jason South

But Japan last week declared a new plan for whaling in the north Pacific Ocean, with the hunt likely to commence before the commission meets again in two years.

Japan will also serve as the next chair of the whaling commission - a move conservation groups have likened to "putting the fox in charge of the hen house".

The ship is about the size of an Olympic pool.Credit:Jason South

Darren Kindleysides from the Australian Marine Conservation Society said Japan had ignored more than 20 resolutions from the commission calling for a stop to so-called "scientific" whaling.

Sea Shepherd has been routinely blasted by Japan for endangering life at sea, with the protest group controversially attempting to disrupt Japan's whalers.

The new vessel was built this year after a charity grant from the Dutch lottery, and was designed by the same shipbuilders that are constructing a new Antarctic ship for the Australian government.

Tied at the same dock is another Sea Shepherd ship, the larger Steve Irwin, dating back to the 1970s and looking far more battered from years of service in rough seas.

At the helm of the Ocean Warrior - what Mr Meyerson calls his office - a trio of digital screens and joy sticks at the fingertips better resemble a space craft, especially compared to the old wooden steering wheel of the Steve Irwin.

Tracking the whaling fleet is the protest group's biggest challenge, more so after Japan declared larger hunting grounds.

Mr Meyerson - a Californian about to embark on his fourth protest campaign in the Southern Ocean - said the Ocean Warrior could have travelled from Amsterdam to Australia on a single tank of fuel.

The ship had sailed to Australia with a crew of 10, he said, but would likely take a few more when departing later in the month for the Southern Ocean.

Daniel Flitton is senior correspondent for The Age covering foreign affairs and politics. He is a former intelligence analyst for the Australian government and was at one-time a university lecturer specialising in international relations.